Adaptive finite element simulation of stack pollutant emissions over complex terrains
TL;DR: In this article, a three-dimensional finite element model for the pollutant dispersion is presented, where the first stage consists on the construction of an adaptive tetrahedral mesh of a rectangular region bounded in its lower part by the terrain and in its upper part by a horizontal plane.
Abstract: A three-dimensional finite element model for the pollutant dispersion is presented. In these environmental processes over a complex terrain, a mesh generator capable of adapting itself to the topographic characteristics is essential. The first stage of the model consists on the construction of an adaptive tetrahedral mesh of a rectangular region bounded in its lower part by the terrain and in its upper part by a horizontal plane. Once the mesh is constructed, an adaptive local refinement of tetrahedra is used in order to capture the plume rise. Wind measurements are used to compute an interpolated wind field, that is modified by using a mass-consistent model and perturbing its vertical component to introduce the plume rise effect. Then, we use an Eulerian convection–diffusion–reaction model to simulate the pollutant dispersion. In this work, the transport of pollutants is considered and dry deposition is formulated as a boundary condition. The discretization of the stack geometry allows to define the emissions as boundary conditions. The proposed model uses an adaptive finite element space discretization, a Crank-Nicolson time scheme, and a splitting operator. This approach has been applied in La Palma island. Finally, numerical results and conclusions are presented.
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TL;DR: In this paper, the authors presented a numerical model to study pollutant dispersion in the atmospheric boundary layer (ABL) by accounting for the mechanisms of advection by the mean wind in the horizontal direction, turbulent diffusion in the vertical direction to ground surface, dry deposition, and radioactive decay.
Abstract: In this paper, we present a numerical model to study pollutant dispersion in the atmospheric boundary layer (ABL). The model accounts for the mechanisms of advection by the mean wind in the horizontal direction, turbulent diffusion in the vertical direction to ground surface, dry deposition, and radioactive decay. More importantly, the model is capable of accounting for the evolution of the ABL structure over a diurnal cycle by considering parameterizations for the wind-speed and eddy-diffusivity profiles that depend on the atmospheric stability condition, which in turn undergoes dramatic changes throughout the day. To solve the resulting advection–diffusion equation, we propose a numerical method based on a stabilized finite element formulation. After validating the numerical model by simulating classical experiments and comparing its predictions with those available in literature, we study the dispersion of a pollutant during a full diurnal ABL cycle with the meteorological parameters generated by AERMET for a 24-h period on a 1-h basis.
20 citations
TL;DR: A new method for wind field forecasting over complex terrain using the predictions of the HARMONIE meso-scale model as the input data for an adaptive finite element mass-consistent wind model with a minimal user intervention.
Abstract: In this paper, we introduce a new method for wind field forecasting over complex terrain. The main idea is to use the predictions of the HARMONIE meso-scale model as the input data for an adaptive finite element mass-consistent wind model. The HARMONIE results (obtained with a maximum resolution of about 1 km) are refined in a local scale (about a few metres). An interface between both models is implemented in such a way that the initial wind field is obtained by a suitable interpolation of the HARMONIE results. Genetic algorithms are used to calibrate some parameters of the local wind field model in accordance to the HARMONIE data. In addition, measured data are considered to improve the reliability of the simulations. An automatic tetrahedral mesh generator, based on the meccano method, is applied to adapt the discretization to complex terrains. The main characteristic of the framework is a minimal user intervention. The final goal is to validate our model in several realistic applications on Gran Canaria island, Spain, with some experimental data obtained by the AEMET in their meteorological stations. The source code of the mass-consistent wind model is available online at http://www.dca.iusiani.ulpgc.es/Wind3D/
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18 citations
TL;DR: The method mixes the benefits resulting from isogeometric analysis, implicit dynamics, residual minimization, and alternating direction solver with direction splitting, and shows that the resulting system of linear equations has a Kronecker product structure, which results in a linear computational cost of the direct solver.
Abstract: In this paper, we propose a novel computational implicit method, which we call Isogeometric Residual Minimization (iGRM) with direction splitting. The method mixes the benefits resulting from isogeometric analysis, implicit dynamics, residual minimization, and alternating direction solver. We utilize tensor product B-spline basis functions in space, implicit second order time integration schemes, residual minimization in every time step, and we exploit Kronecker product structure of the matrix to employ linear computational cost alternating direction solver. We implement an implicit time integration scheme and apply, for each space-direction, a stabilized mixed method based on residual minimization. We show that the resulting system of linear equations has a Kronecker product structure, which results in a linear computational cost of the direct solver, even using implicit time integration schemes together with the stabilized mixed formulation. We test our method on three advection–diffusion computational examples, including model “membrane” problem, the circular wind problem, and the simulations modeling pollution propagating from a chimney.
16 citations
Cites methods from "Adaptive finite element simulation ..."
...We use the pollution model based on [39], with the following simplifying assumptions: we consider only one component of the pollution vector field, we neglect the chemical interactions between different components, and we assume cube shape of the computational domain....
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TL;DR: In this paper, a multimesh adaptive scheme for convection-diffusion-reaction problems for a large number of components is presented, where the evaluation of the nonreactive part for each component and the reaction at each node constitute independent tasks.
Abstract: SUMMARY
A multimesh adaptive scheme for convection–diffusion–reaction problems for a large number of components is presented. The problem is solved by splitting transport and reaction processes. This way, the evaluation of the nonreactive part for each component and the reaction at each node constitute independent tasks. This allows to discretize each component of the solution on a distinct computational mesh, adapted on the basis of its error indicator. The standard single-mesh strategy is used for comparison. Simulations of a point emission in a 3D domain are presented. Low remeshing periods of the adaptive scheme are found to be optimal, in terms of computational cost and accuracy, for the nonreactive problem. Examples with several reaction terms, with an increase of the complexity, are then presented. Results show that the accuracy of single-mesh and multimesh strategies are similar. Instead, the computational cost of the multimesh strategy is lower than the single-mesh in the majority of the examples; this process is controlled by the stiff behavior of the reactive term. The problem size of the multimesh scheme is much lower, and therefore, larger spatial discretizations can be simulated for a given available memory. The efficiency of the multimesh strategy increases with the number of species and the number of species that develop a plume. Finally, an example of a punctual emission considering realistic values of the initial concentrations and using the Community Multiscale Air Quality-CBO5 reaction model, which involves 62 components, is presented; the small-scale structure of the different nitrogen components near the emitter is captured. Copyright © 2013 John Wiley & Sons, Ltd.
11 citations
Cites background from "Adaptive finite element simulation ..."
...The extension to complex geometries (topography and build elements) [16], real wind fields [17], and more realistic stack emissions models [16,18] is left for future developments....
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...This model considers four species and production rates, which are defined as [16, 35]:...
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2,290 citations
"Adaptive finite element simulation ..." refers background in this paper
...For instance, detailed Volatile Organic Components decomposition involves hundreds of thousand reactions [63, 64] that needs special methodologies to reduce the number of the modelled reactions and...
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TL;DR: In this article, two important aerosol species, sulfate and organic particles, have large natural biogenic sources that depend in a highly complex fashion on environmental and ecological parameters and therefore are prone to influence by global change.
Abstract: Atmospheric aerosols play important roles in climate and atmospheric chemistry: They scatter sunlight, provide condensation nuclei for cloud droplets, and participate in heterogeneous chemical reactions. Two important aerosol species, sulfate and organic particles, have large natural biogenic sources that depend in a highly complex fashion on environmental and ecological parameters and therefore are prone to influence by global change. Reactions in and on sea-salt aerosol particles may have a strong influence on oxidation processes in the marine boundary layer through the production of halogen radicals, and reactions on mineral aerosols may significantly affect the cycles of nitrogen, sulfur, and atmospheric oxidants.
1,589 citations
"Adaptive finite element simulation ..." refers background in this paper
...The complete description of photochemical reaction of atmospheric species is highly complex [59, 60, 61, 62]....
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Book•
03 Feb 1984
TL;DR: In this article, an up-to-date summary of the current knowledge of the statistical characteristics of atmospheric turbulence and an introduction to the methods required to apply these statistics to practical engineering problems is presented.
Abstract: Presents, in a single volume, an up-to-date summary of the current knowledge of the statistical characteristics of atmospheric turbulence and an introduction to the methods required to apply these statistics to practical engineering problems. Covers basic physics and statistics, statistical properties emphasizing their behavior close to the ground, and applications for engineers.
1,138 citations
"Adaptive finite element simulation ..." refers background in this paper
...It takes into account the horizontal interpolation and the effect of roughness on the wind velocity [46, 47, 48, 49, 50]....
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TL;DR: OH, NO3, and O3 are shown to play a central role in the formation and fate of airborne toxic chemicals, mutagenic polycyclic aromatic hydrocarbons, and fine particles.
Abstract: Tropospheric air pollution has impacts on scales ranging from local to global. Reactive intermediates in the oxidation of mixtures of volatile organic compounds (VOCs) and oxides of nitrogen (NOx) play central roles: the hydroxyl radical (OH), during the day; the nitrate radical (NO3), at night; and ozone (O3), which contributes during the day and night. Halogen atoms can also play a role during the day. Here the implications of the complex VOC-NOx chemistry for O3 control are discussed. In addition, OH, NO3, and O3 are shown to play a central role in the formation and fate of airborne toxic chemicals, mutagenic polycyclic aromatic hydrocarbons, and fine particles.
1,065 citations
"Adaptive finite element simulation ..." refers background in this paper
...The complete description of photochemical reaction of atmospheric species is highly complex [59, 60, 61, 62]....
[...]
Book•
02 Jun 2003
TL;DR: An introduction to monotonicity-preserving schemes and other stabilization techniques and new trends in fluid dynamics, and main issues in incompressible flow problems.
Abstract: Preface. 1. Introduction and preliminaries. Finite elements in fluid dynamics. Subjects covered. Kinematical descriptions of the flow field. The basic conservation equations. Basic ingredients of the finite element method. 2. Steady transport problems. Problem statement. Galerkin approximation. Early Petrov-Galerkin methods. Stabilization techniques. Other stabilization techniques and new trends. Applications and solved exercises. 3. Unsteady convective transport. Introduction. Problem statement. The methods of characteristics. Classical time and space discretization techniques. Stability and accuracy analysis. Taylor-Galerkin Methods. An introduction to monotonicity-preserving schemes. Least-squares-based spatial discretization. The discontinuous Galerkin method. Space-time formulations. Applications and solved exercises. 4. Compressible Flow Problems. Introduction. Nonlinear hyperbolic equations. The Euler equations. Spatial discretization techniques. Numerical treatment of shocks. Nearly incompressible flows. Fluid-structure interaction. Solved exercises. 5. Unsteady convection-diffusion problems. Introduction. Problem statement. Time discretization procedures. Spatial discretization procedures. Stabilized space-time formulations. Solved exercises. 6. Viscous incompressible flows. Introduction Basic concepts. Main issues in incompressible flow problems. Trial solutions and weighting functions. Stationary Stokes problem. Steady Navier-Stokes problem. Unsteady Navier-Stokes equations. Applications and Solved Exercices. References. Index.
1,035 citations